Nanostructure, electron emitting device, carbon nanotube device, and method of producing the same

A nanostructure comprising:

• a substrate having a surface containing at least one material selected from the group consisting of semiconductors, noble metals, Mn, Fe, Co, Ni, Cu and carbon;
• and
• an anodized film disposed on the surface of said substrate, said anodized film having a nanohole,
• wherein said nanohole passes through said anodized film from the surface of said anodized film to the surface of said substrate, and said nanohole has a first diameter at the surface of said anodized film, and a second diameter at the surface of said substrate, and wherein said second diameter is greater than said first diameter.

An electron emitting device comprising:

• a nanostructure comprising a substrate having a surface containing at least one material selected from the group consisting of semiconductors, noble metals, Mn, Fe, Co, Ni, Cu and carbon, and an anodized film disposed on the surface of said substrate, said anodized film having a nanohole, a carbon nanotube which is embedded in the nanohole such that one end of said carbon nanotube is connected to the surface of said substrate;
• said nanohole passing through said anodized film from the surface of said anodized film to the surface of said substrate, wherein said nanohole has a first diameter at the surface of said anodized film, and a second diameter at the surface of said substrate, and wherein said second diameter is greater than said first diameter;
• an electrode disposed such that said electrode and the surface of said substrate face each other;
• and
• means for applying a voltage between the surface of said substrate and said electrode.

An electron emitting device comprising:

• a nanostructure comprising a substrate having a surface containing at least one material selected from the group consisting of semiconductors, noble metals, Mn, Fe, Co, Ni, Cu and carbon, and an anodized film disposed on the surface of said substrate, said anodized film having a nanohole, a carbon nanotube which is embedded in the nanohole such that one end of said carbon nanotube is connected to the surface of said substrate, said nanohole passing through said anodized film from the surface of said anodized film to the surface of said substrate, wherein said nanohole has a first diameter at the surface of said anodized film, and a second diameter at the surface of said substrate, and wherein said nanohole has a constriction having a diameter smaller than said first and second diameter, at a location between the surface of said anodized film and the surface of said substrate;
• an electrode disposed such that said electrode and the surface of said substrate face each other;
• and
• means for applying a voltage between the surface of said substrate and said electrode.